Biomedical subjects

Y Miyake

Publications and source records attributed to Y Miyake.

At least 775 records · Page 43Linked to original sources

PubMedDate not supplied

Surface topology of collagen fibrils associated with proteoglycans in mouse cornea and sclera.

PURPOSE: To clarify the histological basis for the optical difference in the cornea and sclera, we investigated the surface ultrastructure of D-periodic collagen fibrils. METHODS: The fibril arrangement and topology of D-periodic collagen fibrils from corneas and scleras of mice were examined by transmission and scanning electron microscopy, as well as by atomic force microscopy (AFM). The banding patterns were estimated by densitometry and compared with the profile made by computer simulation from the protein sequence of amino acids. RESULTS: Considerable association of proteoglycans/glycosaminoglycanson XI bands of corneal D-periodic collagen fibrils was seen with ruthenium red staining. Atomic force microscopy imaging showed that the depth of the groove in the D-periodicity of corneal collagen fibrils was shallow compared with that of the sclera. CONCLUSIONS: Corneal collagen fibrils are associated with many extracellular matrix components on both elevated and depressed surfaces of D-periodic bands, which may serve to maintain interfibrillar spaces, resulting in corneal transparency.

Animals↗

PubMedDate not supplied

Estimation of anterior nucleus of lens by Scheimpflug image before and after pupil dilatation.

PURPOSE: To compare the accuracy of lens transparency evaluations by Scheimpflug image in the anterior nucleus of the lens before and after pupil dilatation. METHODS: Scheimpflug lens images were recorded in 70 eyes of 38 subjects (age: 28-75 years) before and after pupil dilatation, and light scattering intensity measurements before and after dilatation were compared. RESULTS: There was a significant positive correlation between the light scattering intensity before and after dilatation at the anterior cortex, anterior nucleus, and central clear zone of the lens (r > 0.9, P <.0001). CONCLUSIONS: It is possible to estimate the transparency in the anterior nucleus of the lens from the Scheimpflug image without pupil dilatation. If nuclear type cataracts are regarded as a structural marker of aging in epidemiological studies, measuring the light scattering intensity in the anterior nucleus of the lens without dilatation seems to be a safe, useful, and quantitative method.

Adult↗

PubMedDate not supplied

Multicenter genetic study of retinitis pigmentosa in Japan: I. Genetic heterogeneity in typical retinitis pigmentosa.

A nationwide, multicenter study of typical retinitis pigmentosa (RP) was carried out in collaboration with 18 hospitals throughout Japan to obtain current information for genetic counseling. We analyzed the genetic heterogeneity of RP based on the parental consanguinity of 434 probands registered during a 6-month period in 1990. A gradual decline in the frequency of consanguineous marriage was recognized among the normal parents of RP patients. The relative frequencies of inheritance patterns were estimated as: autosomal recessive, 25.2%; autosomal dominant, 16.9%; X-linked, 1.6%; and simplex, 56.3%. A comparison of these results with previous reports in Japan revealed a decline in the relative frequency of autosomal recessive cases and an increase in simplex cases. This suggests a decrease in the incidence of autosomal recessive retinitis pigmentosa in Japan, as well as the necessity for exhaustive investigations aimed at identifying inheritance patterns for RP patients seeking genetic counseling.

Adolescent↗

PubMedDate not supplied

Multicenter genetic study of retinitis pigmentosa in Japan: II. Prevalence of autosomal recessive retinitis pigmentosa.

Retinitis pigmentosa (RP) is a group of genetically heterogeneous diseases with autosomal recessive (AR), autosomal dominant, and X-linked modes of inheritance. Autosomal recessive retinitis pigmentosa (ARRP) is the most common form in Japan. A genetic analysis was done to determine the prevalence of ARRP indirectly, to provide an estimation of changing trends in the overall prevalence of RP. Data on the frequency of consanguinity and marriage year of normal parents of 59 ARRP patients were obtained from a nationwide multicenter survey of typical retinitis pigmentosa conducted in 1990. The gene frequency of ARRP was 0.01145 (Dahlberg's formula). In 1990, the number of young symptomatic ARRP patients decreased, while the number of patients aged 40 years and older increased. The total number of symptomatic ARRP patients in 1990 was nearly 21% higher than in 1970. Despite a dramatic decline in consanguinity in recent decades in Japan, the number of ARRP patients has increased. This increase is attributed to greater longevity and overall population growth. Our results suggest that the total number of RP patients has not decreased, and may even have increased.

Adolescent↗

PubMedDate not supplied

Extrafoveal photostress recovery testing with a scanning laser ophthalmoscope.

We used a modified photostress recovery test (PSRT) with microperimetry in a scanning laser ophthalmoscope (SLO) to evaluate the extrafoveal region. After the red-target threshold was determined, the retina was bleached with argon green laser illumination. Test spots were presented every 3 seconds at the testing point and subjects indicated when they saw the spot. We determined the recovery time in 17 normal subjects under the following conditions: bleaching times of 10, 20, and 30 seconds; spot intensities of 0, 2, and 4 dB greater than threshold; Goldmann I, II, and III spots; and spot locations 7.5 degrees temporal to, nasal to, above and below the fovea, and at the fovea. We also measured recovery times inside and outside the detachment in 11 patients with central serous chorioretinopathy. Recovery time was correlated with bleaching time and spot intensity, but not with the location of spot size in normal subjects. In patients with chorioretinopathy, the recovery time was longer inside than outside the detachment. This technique is useful for measurement of photostress recovery time at extrafoveal points, and for comparison of times at various testing points. Results in patients with chorioretinopathy suggest that this technique may be useful for studying the pathophysiology in ocular diseases.

Adult↗

PubMedDate not supplied

Effect of age on short-wavelength sensitive cone electroretinogram and long- and middle-wavelength sensitive cone electroretinogram.

Using a light-emitting diode (LED) built-in contact lens electrode, we studied the effect of age on short-wavelength sensitive cone electroretinograms (S-cone ERG) and long- and middle-wavelength sensitive cone ERGs (LM-cone ERG). We recorded ERGs in 31 pseudophakic subjects to avoid the effect of yellowing in the human crystalline lens. The intensities of our stimuli were on the asymptote of the intensity-response curve. Linear regression analysis against age was carried out on the S-cone ERG b-wave, and the LM-cone ERG a-, b-, and d-waves. We found significant age-dependent reduction in the amplitude of the S-cone ERG b-wave, and the LM-cone ERG a- and d-waves, significant prolongation in the peak time of the S-cone b-wave and the LM-cone ERG b-wave, significant increase in the b/a ratio of the LM-cone ERG, but no significant age correlation between the LM-cone ERG a-wave and the amplitude of the b-wave. Our results provide evidence that age-related changes in S- and LM-cone systems begin in early adulthood in the human eye. A significant increase in the b/a ratio suggests that off-bipolar cells are more vulnerable to aging than on-bipolar cells.

Adult↗

PubMedDate not supplied

Kinetics of foveal cone photopigment in myopia without chorioretinal degeneration.

PURPOSE: To study the early changes in the outer retina of myopic eyes, we performed fundus reflection foveal cone densitometry in 45 subjects with normal visual acuity and no chorioretinal degeneration (ages: 18-47 years, refraction; +2.00-(-14.50) diopters). METHODS: After full bleaching, the density of the photopigment was measured for 7 minutes by using a test spot, 562 nm in wavelength and 1 degrees in diameter, focused on the fovea. We calculated the density difference (DD) and the time constant (TC) of photopigment regeneration. RESULTS: Although we found no correlation between the DD and the refractive error, there was a significant increase in TC as the refractive error increased (r = 0.50, P < 0.01). CONCLUSIONS: These findings indicated that the kinetics of cone pigments become abnormal preceding the loss of cone cells or chorioretinal degeneration in high myopia.

Adolescent↗

PubMedDate not supplied

Amplitude decrease of photopic ERG b-wave at higher stimulus intensities in humans.

PURPOSE: The b-wave of the human photopic electroretinogram (ERG) elicited by a short-flash increases in amplitude with increasing stimulus intensities at lower stimulus levels, but then decreases at higher stimulus intensities. The purpose of the present study was to explore this phenomenon in more detail, using short- and long-flash stimuli. METHODS: The intensity-response functions of the b-wave elicited by short- and long-flashes were compared from threshold to higher stimulus intensities in 5 normal subjects. Short- and long-flash ERGs were elicited under rod-saturating background levels using white light-emitting diodes built into a contact lens electrode. RESULTS: Whereas the amplitude of the short-flash b-wave decreased at higher intensities, the amplitude of the long-flash ERG b-wave did not decrease but plateaued. The long-flash ERG d-wave or OFF-response decreased at higher stimulus levels as did the short-flash elicited b-wave. CONCLUSIONS: Because it is widely accepted that the b-wave and the OFF-response d-wave interact to produce a single positive response, our results suggest that the decrease in the b-wave amplitude at high stimulus intensity is caused by the decrease of the d-wave at the higher stimulus intensities.

Adaptation, Ocular↗

PubMedDate not supplied

Clinical utility and validation of the Japanese version of Memorial Delirium Assessment Scale in a psychogeriatric inpatient setting.

Delirium is a common mental disorder in the elderly. The Memorial Delirium Assessment Scale (MDAS) was developed in 1997 to assess delirium severity over time. The purpose of the current prospective study is to assess the clinical utility, diagnostic potential, reliability and validity of the Japanese version of MDAS in a psychogeriatric unit setting. Reliability was examined by testing 37 elderly patients; validity was examined concurrently by 16 patients with delirium. Two psychiatrists evaluated each patient simultaneously. Mean MDAS ratings differed among groups of patients with delirium, dementia, or no cognitive impairment. High levels of consistency within raters (Cronbach's alpha=0.92) and reliability between raters (0.98) were indicated. The correlation between MDAS scores and rating on the Delirium Rating Scale (r=.74, P=.0011), the Clinician's Global Rating of delirium severity (r=.67, P=.0047), and the Mini Mental State Examination (r=-.54, P=.029) was fair. The MDAS seems to be a reliable measuring instrument for assessing delirium in elderly patients.

Aged↗

PubMedDate not supplied

Effect of ultrafiltration on priming solution with preserved blood for extracorporeal circulation in infants.

In pediatric cardiac surgery, the initial priming solutions of the extracorporeal circulation include preserved blood. In an effort to eliminate unfavorable effects of preserved blood on the circulation, the authors introduced the preserved blood to ultrafiltration (UF). Seventeen infants with congenital heart defects were included in this study. UF was performed with a polysulfone ultrafiltrator before extracorporeal circulation. The 1600 ml of fluid, consisting of saline, 5% glucose, and maltose, were added to 400 ml of preserved blood, and the same amount of fluid was removed by UF. The concentrations of potassium, NH3, and bradykinin in the priming blood decreased significantly after UF. In the UF group, water balance during extracorporeal circulation and max. Creatinine-phosphokinase levels after surgery were better than controls. These data suggest that UF is able to remove some substances and result in reduction of an unfavorable effect on the circulation.

Blood Preservation↗

PubMedDate not supplied

High [18F]FDG uptake in primary cerebral lymphoma: a PET study.

Two cases of primary intracranial malignant lymphoma with high uptake of [18F]fluorodeoxyglucose [( 18F]FDG) are reported. Malignant lymphomas should be considered in the differential diagnosis of brain tumors with high [18F]FDG uptake in positron emission tomography studies.

Aged↗

PubMedDate not supplied

High [18F]-fluorodeoxyglucose uptake in abdominal abscesses: a PET study.

We report two cases of abdominal abscess displaying high uptake of [18F]fluorodeoxyglycose (FDG) by positron emission tomography (PET). Abdominal abscesses should be considered in the differential diagnosis of abdominal masses showing high FDG uptake in PET studies.

Abdominal Neoplasms↗

PubMedDate not supplied

Surgical results of vitrectomy in ocular trauma.

The authors have analyzed 49 consecutive eyes with trauma that had undergone vitrectomy. Anatomic success (eyes with attached retinas and generally clear media, regardless of visual function) was achieved in 80% of eyes. This high rate of success resulted from the use of silicone oil in 20 eyes with complicated retinal detachment that was judged otherwise as irreversible. Functional success (eyes with a final visual acuity of 0.2 [20/100] or better, or a postoperative improvement in visual acuity of two lines on the Snellen chart) was achieved in 53% of eyes. In most of the eyes that underwent vitrectomy 2 months or longer after injury, the visual outcome was poor, even when anatomic success was achieved. Retinal detachment was a major factor in poor surgical prognosis. Prophylactic scleral buckling and/or an encircling procedure significantly decreased the incidence of postoperative retinal detachment.

Accidents, Occupational↗

PubMedDate not supplied

Coxa magna after open reduction for developmental dislocation of the hip.

We studied coxa magna after open reduction of developmental hip dislocation, including the etiology, incidence, and influence on the long-term results and acetabular development. Forty-seven hips in 47 patients were radiographically examined for at least 10 years, and another 20 hips in 20 patients were examined arthrographically at an early stage after open reduction. At follow-up, the incidence of coxa magna, which was defined as a femoral head with a size > or = 20% greater than the opposite side, was 34.0%, and that seemed to be one of factors that worsened the long-term results. One of the most important causes of coxa magna is to overwiden the acetabular capacity by excising the limbus; another cause is the surgical invasion and synovitis of the hip joint after operation.

Child, Preschool↗

PubMedDate not supplied

Evaluation of four warming procedures to minimise heat loss induced by anaesthesia and surgery in dogs.

OBJECTIVE: To evaluate the efficiency of four warming procedures, introduced after anaesthetic induction and continued during surgery, in minimising heat loss in anaesthetised dogs. DESIGN: Dogs were paired. One of each pair was a control; the other was subjected to one of four warming procedures. METHODS: Ninety-six dogs were involved in total. Pairs of dogs were matched for breed, hair length, and type of surgical procedure and placed adjacent to each other in a large temperature-controlled surgical theatre. One dog within each pair was assigned to one of four warming procedures that commenced immediately after anaesthetic induction. Group 1 (11 pairs) were placed on a purpose-designed prewarmed (41 degrees C) electrically heated pad. Group 2 (18 pairs) were placed on a prewarmed electric heat pad (41 degrees C), cocooned by four wrapped water bottles (initially 41 degrees C) and subjected to radiant heat (150 watt lamp placed 50 cm away from the head of the dog). Group 3 (11 pairs) were surrounded by a forced air warming mattress (set at 43 degrees C). Group 4 (8 pairs) were connected via the anaesthetic breathing circuit to a heater/humidifier (set at 41 degrees C). Rectal temperature measurements were recorded every 15 min for the first 3 h of anaesthesia. The fall in rectal temperature of the control dog was subtracted from the fall in temperature of the treatment dog and this measurement was used to assess the efficacy of the various warming procedures. RESULTS: The mean rectal temperature of unheated 'control' dogs decreased 1.9 +/- 0.6, 1.4 +/- 0.4 and 1.1 +/- 0.4 degrees C over the first, second and third hour respectively. After 3 h the temperature fall differential for all groups were 0.7 +/- 0.7 (Group 1), 3.1 +/- 1.1 (Group 2), 2.4 +/- 1.1 (Group 3) and 1.0 +/- 1.1 degrees C (Group 4). Thus the group 2 procedure was the most successful in preventing a drop of temperature followed by groups 3, 4 and 1. CONCLUSION: Large dogs undergo significant reduction in core body temperature especially during the first 2 h of anaesthesia and surgery. Supplementary warming substantially reduces this fall in body temperature, although certain warming procedures were found to be more effective than others.

Anesthesia, General↗

PubMedDate not supplied

Effect of Varidase (streptokinase) on biofilm formed by Staphylococcus aureus.

Staphylococcus aureus forms a fibrin-rich biofilm in the presence of plasma which is highly resistant to attack by the human immune system and to chemotherapy. Varidase, composed mainly of streptokinase, is used for hydrolyzing clots. In this study, we attempted to destroy the biofilm of S. aureus with Varidase and to apply this drug in the treatment of staphylococcal infections. Four clinical isolates were used in the experiments. These organisms formed a several-millimeter-thick biofilm on type IV collagen coated coverslips in trypticase soy broth containing 50% human plasma. The biofilm was composed of bacterial cell which adhered to fibrillar fibers and of sediment derived from plasma. 10,000 U/ml of Varidase, the dose which is used clinically, removed the sediment and reduced the number of live bacteria in biofilms to less than 20% of control. 200 U/ml of Varidase was also effective against biofilms of the organisms. An equal combination of Varidase and ofloxacin had an additive effect on the bacteria. The results of this study demonstrate that Varidase is highly effective in destroying biofilms of S. aureus in vitro and suggest that this drug would be useful for treating staphylococcal infections.

Biofilms↗

PubMedDate not supplied

Blue-on-yellow perimetry to evaluate S cone sensitivity in diabetics.

Blue-on-yellow (B/Y) perimetry was performed on 31 patients with non-insulin-dependent diabetes mellitus to study the loss of sensitivity to short wavelengths. Of these patients, 21 were without retinopathy (NDR) and 10 had early background retinopathy (SDR). Eleven normal subjects served as controls. The results were compared to white-on-white (W/W) perimetry. Foveal sensitivity determined by B/Y and W/W perimetry showed no significant difference between NDR, SDR and normals. However, the mean sensitivity in the central 30-degree area and that in the upper half of the central 20- to 30-degree concentric circular field were significantly decreased in B/Y perimetry in SDR patients (p < 0.05, p < 0.01, respectively). No significant sensitivity loss was detected in the W/W test. We conclude that there is a blue cone system sensitivity loss in the central 30-degree area, particularly in the upper half of the visual field and the paracentral area in diabetic patients with early background retinopathy.

Adult↗

PubMedDate not supplied

Cytologic features of pleural effusion in apocrine sweat gland carcinoma. A case report.

BACKGROUND: Carcinoma arising in the apocrine sweat glands is very rare, and there are few reports of the cytologic features. We encountered a case of metastatic apocrine carcinoma in a pleural effusion. CASE: A 46-year-old male had a dark reddish nodule in the right axillary region that was diagnosed as apocrine carcinoma of skin appendage origin. Three years after wide resection and chemotherapy, widespread metastases developed with a massive pleural effusion. Needle aspiration fluid cytology contained clusters of adenocarcinoma. Some tumor cells had abundant cytoplasm or periodic acid-Schiff-positive, coarse granules. Decapitation secretion was occasionally found on the cell surface. Immunohistochemically, the tumor cells were often positive for BRST-2 and BRST-3. CONCLUSION: Cytologic features of metastatic apocrine sweat gland carcinoma show some characteristics of adenocarcinoma. Moreover, its definitive diagnosis in a pleural effusion can be made because of retaining the characteristics of apocrine sweat gland.

Apocrine Glands↗